Magnetic field formation device, power supplying device, power receiving device, power receiving/supplying device, and portable device

ABSTRACT

A magnetic field is formed at a predetermined region. A magnetic field formation device configured to generate a variable magnetic field at a predetermined region A includes: at least one power supplying resonator configured to generate the variable magnetic field; and power-supplying coils configured to generate an induced current in the at least one power supplying resonator, all of the power-supplying coils and the at least one power supplying resonator being disposed so that coil surfaces oppose the predetermined region A, and at least one of the power-supplying coils being disposed to have a coil surface direction which intersects with coil surface directions of the other power-supplying coils.

TECHNICAL FIELD

The present invention relates to a magnetic field formation deviceforming a magnetic field at a predetermined region, a power-supplyingdevice, a power-receiving device, a power receiving/supplying device,and a mobile device.

BACKGROUND

A structure of wireless power transmission from a power feeding coil toa power-receiving coil by electromagnetic induction or magnetic fieldresonance has been proposed (e.g., Patent Literature 1 and PatentLiterature 2).

CITATION LIST Patent Literature

[Patent Literature 1] Japanese Unexamined Patent Publication No.2015-144508

[Patent Literature 2] Japanese Unexamined Patent Publication No.2013-240260

SUMMARY OF INVENTION Technical Problem

In regard to the above, the known arrangements were done focusing oneffects such as improvement in power transmission efficiency based onpower transmission, and there have been no arrangements based onformation of a magnetic field at a predetermined region.

An object of the present invention is to provide a magnetic fieldformation device forming a magnetic field at a predetermined region, apower-supplying device, a power-receiving device, a powerreceiving/supplying device, and a mobile device.

Solution to Problem

According to the present invention, a magnetic field formation device isconfigured to generate a variable magnetic field at a predeterminedregion, including: at least one power supplying resonator configured togenerate the variable magnetic field; and power-supplying coilsconfigured to generate an induced current in the at least one powersupplying resonator, all of the power-supplying coils and the at leastone power supplying resonator being disposed so that coil surfacesoppose the predetermined region, and at least one of the power-supplyingcoils being disposed to have a coil surface direction which intersectswith a coil surface direction of at least one of the otherpower-supplying coils. The magnetic field formation device of thepresent invention may generate a variable magnetic field at apredetermined region, all of the power-supplying coils may be disposedso that coil surfaces oppose the predetermined region, and at least oneof the power-supplying coils may be disposed to have a coil surfacedirection which is parallel to a coil surface direction of at least oneof the other power-supplying coils.

According to the arrangements above, a variable magnetic field with highmagnetic field strength or low magnetic field strength can be formed ata part of the predetermined region by the variable magnetic fields ofthe power-supplying coils and the variable magnetic field of the powersupplying resonator, based on the positional relation between thepower-supplying coils and the power supplying resonator. This isachieved by adjusting the angles, locations, etc. of the coil surfacesof the power-supplying coils.

The magnetic field formation device of the present invention may furtherinclude a current output controller which is configured to output avariable current to one of output targets which are at least one of andnot all of the power-supplying coils and to be capable of switching theoutput target to which the variable current is output.

According to this arrangement, it is possible to change the distributionof the magnetic field strength of a variable magnetic field by sending amagnetic field from each power-supplying coil to the power-supplyingcoil functioning as the power supplying resonator at a different angle.Furthermore, as the power supplying resonator resonates on account ofthe variable magnetic field of each of the power-supplying coils, themagnetic field strength of the variable magnetic field at thepredetermined region is enhanced.

The magnetic field formation device of the present invention may bearranged such that the current output controller executes a stop processof not outputting the variable current to any of the power-supplyingcoils, with a predetermined condition of a timing and a duration.

With this arrangement, it is possible to easily generate a variablemagnetic field with predetermined magnetic field strength inconsideration of heat generation and power consumption, by adjusting thetiming and duration of the stop process.

The present invention relates to a power-supplying device including oneof the above-described magnetic field formation devices.

The present invention relates to a power-receiving device including apower-receiving mechanism which is configured to receive power by avariable magnetic field generated at a predetermined region by any oneof the above-described magnetic field formation devices.

The power-receiving device of the present invention may include apower-receiving mechanism configured to receive power by the variablemagnetic field; and a high-capacitance capacitor which has a capacity ofbeing charged by a current received by the power-receiving mechanism anddischarging at least at a minimum operating voltage of an electric parton a subsequent stage while an output target of the variable current bythe current output controller is being switched.

According to the arrangement above, even when an induced current cannotbe easily obtained from the power-receiving mechanism on account of theswitching of the output target of the variable current, the electricpart is stably driven because the high-capacitance capacitor performsthe discharge at least at the minimum operating voltage of the electricpart.

The high-capacitance capacitor of the power-receiving device of thepresent invention may have a capacity of discharging at least at theminimum operating voltage of the electric part on the subsequent stageduring a stop process in which the current output controller does notoutput the variable current to any of the power-supplying coil.

According to this arrangement, in addition to the period during whichthe switching of the output target of the variable current is beingperformed by the current output controller, even when an induced currentcannot be obtained from the power-receiving mechanism due to the stopprocess for the power-supplying coil and the power supplying resonator,the electric part is stably driven as the high-capacitance capacitorperforms the discharge at least at the minimum operating voltage of theelectric part.

The present invention relates to a power receiving/supplying deviceincluding: a power-supplying device including any one of theabove-described magnetic field formation devices; and a power-receivingdevice including a power-receiving mechanism which is configured toreceive power by the variable magnetic field generated by thepower-supplying device.

The present invention relates to a mobile device including apower-receiving mechanism which is configured to receive power by avariable magnetic field generated at a predetermined region by any oneof the above-described magnetic field formation devices.

Advantageous Effects

According to the present invention, a magnetic field which is partiallya variable magnetic field with high or low magnetic field strength canbe formed at the predetermined region.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic explanatory diagram of a magnetic field formationdevice in a front view.

FIG. 2 is a schematic explanatory diagram of a magnetic field formationdevice in a front view.

FIG. 3A is a schematic explanatory diagram of a magnetic field formationdevice in a front view.

FIG. 3B is a schematic explanatory diagram of a magnetic field formationdevice in a front view.

FIG. 4 is a schematic explanatory diagram of a magnetic field formationdevice in a front view.

FIG. 5 is a schematic explanatory diagram of a magnetic field formationdevice in a plan view.

FIG. 6 is a schematic explanatory diagram of a magnetic field formationdevice in a plan view.

FIG. 7 is a block diagram of a magnetic field formation device.

FIG. 8 is an explanatory diagram of operations of a current pathswitcher.

FIG. 9 is a block diagram of a power receiving/supplying device.

FIG. 10 is a block diagram of a driving device.

FIG. 11 is a block diagram of a driving device.

FIG. 12 is a block diagram of a driving device.

DESCRIPTION OF EMBODIMENTS

The following will describe an embodiment of the present invention withreference to drawings. (Magnetic Field Formation Device: Overview)

As shown in FIG. 1, a magnetic field formation device 101 is configuredto generate a variable magnetic field at the predetermined region A. Tobe more specific, the magnetic field formation device 101 includes atleast one power supplying resonator 121 configured to generate avariable magnetic field and power-supplying coils 111 and 112 configuredto generate an induced current in the power supplying resonator 121. Allof the power-supplying coils 111 and 112 and all of the power supplyingresonator 121 are provided so that coil surfaces 111 a, 112 a, and 121 aoppose the predetermined region, and at least one of the power-supplyingcoils 111 and 112 is provided to have a coil surface directionintersecting with the coil surface direction of the other one of thepower-supplying coils 111 and 112. The coil surface direction is adirection in parallel to a coil surface.

Alternatively, as shown in FIG. 2, at least one of the power-supplyingcoils 111 and 112 may be provided to have a coil surface directionparallel to the coil surface direction of the other one of thepower-supplying coils 111 and 112. In this case, the power-supplyingcoils 111 and 112 may be arranged so that the coil surfaces 111 a and112 a having the coil surface directions parallel to each other sandwichat least a part of the predetermined region A. Furthermore, in the caseabove, the power-supplying coils 111 and 112 may be disposed to at leastpartially overlap each other when one of the coil surfaces 111 a and 112a having the coil surface directions parallel to each other is projectedonto the other coil surface in the direction along the coil axis.

Alternatively, the power-supplying coils 111 and 112 may be disposed sothat the coil surface 111 a or 112 a of at least one of thepower-supplying coils 111 and 112 and the coil surface 111 a or 112 a ofthe other one of the power-supplying coils 111 and 112 are not on thesame plane.

In the magnetic field formation device 101 structured as above, avariable magnetic field with high magnetic field strength or lowmagnetic field strength can be formed at a part of the predeterminedregion A by the variable magnetic fields of the power-supplying coils111 and 112 and the variable magnetic field of the power supplyingresonator 121, based on the positional relation between thepower-supplying coils 111 and 112 and the power supplying resonator 121.This is achieved by adjusting the angles, locations, etc. of the coilsurfaces 111 a and 112 a of the power-supplying coils 111 and 112. Inthis way, a magnetic field which is partially a variable magnetic fieldwith high or low magnetic field strength can be formed at thepredetermined region A.

The “variable magnetic field” indicates one of (1) a magnetic field in astate in which the direction of the magnetic lines of force alternatelychanges between the forward direction and the reverse direction, (2) amagnetic field in a state in which the magnetic field strength changeswhile the direction of the magnetic lines of force is the forwarddirection, (3) a magnetic field in a state in which the magnetic fieldstrength changes while the direction of the magnetic lines of force isthe reverse direction, and (4) a magnetic field in a state in which twoor more of the states (1) to (3) are combined.

The “predetermined region A” may be of any size or shape. Thepredetermined region A is a reverse frustum in shape, in which the lowerface is smaller in diameter than the upper face. The reverse frustumshape may be a reverse circular frustum shape, a reverse square frustumshape, or an N-sided frustum shape. While in the present embodiment thepredetermined region A is reverse frustum in shape, the disclosure isnot limited to this arrangement. In other words, as shown in FIG. 3A,the inclination angle of at least one side face may be different fromthe inclination angles of the remaining side faces in the predeterminedregion A, or the predetermined region A may be a frustum in which thelower face is larger in diameter than the upper face as shown in FIG.3B. The predetermined region A may be sized and shaped to correspond toan object provided in the variable magnetic field, or may be sized andshaped to correspond to a receiving space such as a container, a housingbox, a room, etc. in which the object is housed. The “predeterminedregion A: may be a hexahedron such as a rectangular parallelepiped body,a cube, or a triangular prism.

An example of the “object” is a driving device including apower-receiving device to which power is supplied by a variable magneticfield. The driving device encompasses all types of devices driven byelectric power. Examples are a mobile device, a home electric appliance,and an automobile.

(Magnetic Field Formation Device: Power Supplying Resonator)

The “power supplying resonator 121” is of a spiral type, a solenoidtype, or a loop type, for example, and is a coil in which the ends ofthe coil are directly connected (short-circuited) to each other orindirectly connected (short-circuited) to each other by a GND or thelike. The power supplying resonator 121 is provided so that a coilsurface 121 a opposes the lower bottom of the predetermined region A.With this arrangement, when an induced current is supplied, the powersupplying resonator 121 generates a variable magnetic field at thepredetermined region A opposing the coil surface 121 a and generates avariable magnetic field at a region opposite to the predetermined regionA over the power supplying resonator 121.

The coil surface 121 a of the power supplying resonator 121 is sized andshaped to correspond to the size and shape of the bottom of thepredetermined region A. For example, as shown in FIG. 4, the coilsurface 121 a of the power supplying resonator 121 may be circular inshape to correspond to the size of the predetermined region A, or mayhave another shape. To be more specific, the coil surface 121 a may betriangular as in a power supplying resonator 121A, the coil surface 121a may be quadrangular as in a power supplying resonator 121B, or thecoil surface 121 a may have another shape such as polygonal orelliptical. The shape of the coil surface 121 a of the power supplyingresonator 121 may correspond to the shape of the bottom of thepredetermined region A, or may be determined in accordance with factorssuch as the disposition of the other power-supplying coils 111 and 112.

The number of the power supplying resonator 121 is one or more. Whenthere are plural power supplying resonators 121, each of the powersupplying resonators 121 may have a coil surface with a desired shape,as resonator sub coils 1211 which are identical or different in size aregathered. Alternatively, a power supplying resonator 121 may be formedof an annular resonator sub coil 1212 corresponding to the coil surfaceshape and resonator sub coils 1211 provided on the inner circumferentialside of the resonator sub coil 1212. When the power supplying resonator121 is formed by plural resonator sub coils 1211 (1212), it is possibleto finely adjust the magnetic field strength of a variable magneticfield generated by each resonator sub coil 1211 (1212).

(Magnetic Field Formation Device: Power-Supplying Coil)

The “power-supplying coils 111 and 112” are of a spiral type, a solenoidtype, or a loop type, for example, and are coils which generate aninduced current at a power supplying resonator 121 on account of anexternally-supplied variable current. The “variable current” indicatesone of (1) a current which alternately varies to the positive side andthe negative side over 0 ampere, (2) a current which varies on thepositive side, (3) a current which varies on the negative side, and (4)a current in a state in which two or more of the states (1) to (3) arecombined.

All of the power-supplying coils 111 and 112 are provided so that coilsurfaces 111 a and 112 a oppose the predetermined region, and at leastone of the power-supplying coils 111 and 112 is provided to have a coilsurface direction intersecting with the coil surface direction of theother one of the power-supplying coils 111 and 112. For example in caseof the magnetic field formation device 101, 101A including thepredetermined region A as shown in FIG. 1 and FIG. 3A, thepower-supplying coils 111 and 112 are disposed along the side faces ofthe predetermined region A and hence the coil surface directionsintersect with each other at a location below the predetermined regionA. In case of the magnetic field formation device 101B including thepredetermined region A as shown in FIG. 3B, the power-supplying coils111 and 112 are disposed along the side faces of the predeterminedregion A and hence the coil surface directions intersect with each otherat a location above the predetermined region A.

While in FIG. 1 to FIG. 3B two power-supplying coils 111 and 112 areprovided for convenience of explanation, the number of thepower-supplying coils is not limited to this. The number of thepower-supplying coils may be variously set on condition that the numberis two or more. Alternatively, for example, as shown in FIG. 5, whenviewed from a point above the predetermined region A, threepower-supplying coils 111, 112, and 113 may be provided along therespective sides of an equilateral triangle which is centered at thepredetermined region A. In this case, the state of the end face cutalong the X-X line in FIG. 5 corresponds to the positional relationbetween the power-supplying coils 111 and 112 shown in FIG. 1.

Alternatively, for example, as shown in FIG. 6, when viewed from a pointabove the predetermined region A, four power-supplying coils 111, 112,113, and 114 may be provided along the respective sides of a squarewhich is centered at the predetermined region A. In this case, the stateof the end face cut along the X-X line in FIG. 5 corresponds to thepositional relation between the power-supplying coils 111 and 112 shownin FIG. 1.

As shown in FIG. 4, the coil surfaces of the power-supplying coils 111and 112 have sizes and shapes corresponding to those of the side facesof the predetermined region A. For example, the coil surfaces 111 a and112 a of the power-supplying coils 111 and 112 may be formed to betrapezoidal to correspond to the predetermined region A having a reversefrustum shape, or to be elliptical (power-supplying coil 111A). Each ofthe coil surfaces of the power-supplying coils 111 and 112 may be, forexample, circular, triangular, quadrangular, or polygonal in shape tocorrespond to the size of the predetermined region A. The shapes of thecoil surfaces 111 a and 112 a of the power-supplying coils 111 and 112may be different from each other. The coil surfaces 111 a and 112 a ofthe power-supplying coils 111 and 112 may be formed to correspond to aprojected shape of a side face of the predetermined region A, or may beformed in accordance with factors such as the disposition of the otherpower-supplying coils 111 and 112 and the power supplying resonator 121.

Each of the power-supplying coils 111 and 112 may be formed of pluralpower supplying sub coils. For example, in the power-supplying coil 111,a coil surface 11 a which is trapezoidal on the whole may be formed bygathering power supplying sub coils 1111 which are identical ordifferent in size. Alternatively, in the power-supplying coil 111, acoil surface 111 a which is trapezoidal on the whole may be formed bygathering power supplying sub coils 1111 and power supplying sub coils1112 which are different in shape from the power supplying sub coils1111 and each of which is trapezoidal, for example.

The power-supplying coils 111 and 112 may be disposed so that the outerperipheries thereof partially overlap each other. With this arrangement,the magnetic field strength is easily uniformized by causing the outerperipheries of the power-supplying coils 111 and 112 with low magneticfield strength to overlap each other.

(Magnetic Field Formation Device: Oscillation Controller)

As shown in FIG. 7, the magnetic field formation device 101 structuredas described above includes the oscillation controller 131 (which is anexample of a current output controller) connectable to an external powersource PS. While a magnetic field formation device 101 including threepower-supplying coils 111, 112, and 113 will be described below, thedisclosure is not limited to this arrangement.

The oscillation controller 131 includes an oscillator 1312 and a currentpath switcher 1311. The oscillator 1312 is connected to a power sourcePS and is capable of outputting a variable current. The current pathswitcher 1311 is configured to output a variable current of theoscillator 1312 to one of output targets which are at least one of andnot all of the power-supplying coils 111, 112, and 113 and to be capableof switching the output target to which the variable current is output.With this, the oscillation controller 131 is able to change thedistribution of the magnetic field strength of a variable magneticfield, as the power-supplying coils 111, 112, and 113 send a magneticfield to the power supplying resonator 121 at a different angle.Furthermore, as the switching is repeated, a variable magnetic field inwhich an amount of change of the magnetic field strength is uniformizedis formed at the predetermined region A as compared to cases where thepositional relation between the power-supplying coils 111, 112, and 113and the power supplying resonator 121 is fixed. Furthermore, as thepower supplying resonator 121 resonates on account of the variablemagnetic field of each of the power-supplying coils 111, 112, and 113,the magnetic field strength of the variable magnetic field at thepredetermined region A is enhanced.

(Magnetic Field Formation Device: Oscillation Controller: Oscillator)

The oscillator 1312 is configured to receive a current outputted fromthe power source PS and is capable to outputting a variable current withany oscillating frequency. The oscillating frequency of the oscillator1312 is preferably changeable to allow for the use of various types ofmagnetic field formation devices 101. Furthermore, each of theoscillating frequency, the voltage, and the current of the oscillator1312 may be changeable in accordance with the specification of thepower-supplying coil 111, 112, or 113 which is the output target.

The current output target controller is required to output a variablecurrent to one of output targets which are at least one of and not allof the power-supplying coils and to be capable of switching the outputtarget to which the variable current is output. The current outputtarget controller is therefore not limited to the above-describedoscillation controller 131 of the embodiment. While in the presentembodiment the oscillator 1312 is indirectly connected to thepower-supplying coils 111, 112, and 113 via the current path switcher1311, the oscillator 1312 may be directly connected to thepower-supplying coils 111, 112, and 113. In this case, the variablecurrent from the oscillator 1312 can be supplied to all power-supplyingcoils 111, 112, and 113. Alternatively, the current path switcher 1311may be connected to the power source PS and the oscillator 1312 may beprovided on each of current paths connecting the current path switcher1311 with the respective power-supplying coils 111, 112, and 113. Inthis case, the current path switcher 1311 is able to switch thepower-supplying coil which is the output target of the variable current,by switching the output target of the current output from the powersource PS between the three oscillators 1312 provided for the respectivecurrent path switchers 1311.

(Magnetic Field Formation Device: Oscillation Controller: Current PathSwitcher)

As shown in FIG. 8, the current path switcher 1311 includes a switchmechanism which is configured to switchably output the variable currentof the oscillator 1312 to each of the power-supplying coils 111, 112,and 113. The switch mechanism includes plural switches. Each of theseswitches is switchable between connection (on-state) and disconnection(off-state) of an input end and an output end. The input ends of allswitches are connected to the oscillator 1312. Meanwhile, the outputends are connected to the respective power-supplying coils 111, 112, and113. With this arrangement, the switch mechanism supplies a variablecurrent from the oscillator 1312 to only one of the power-supplyingcoils 111, 112, and 113, which is connected to a switch in the on-state.

Furthermore, the current path switcher 1311 includes a switch controlmechanism. The switch control mechanism is able to switch each switch ofthe switch mechanism between the on-state and the off-state. Forexample, provided that a route through which the variable current issupplied to the power-supplying coil 111 is a route A, a route throughwhich the variable current is supplied to the power-supplying coil 112is a route B, and a route through which the variable current is suppliedto the power-supplying coil 113 is a route C, there are six connectionpatterns 1 to 6. In other words, in the present embodiment, there aresix output targets as an output target of the variable current from theoscillator 1312.

To be more specific, there are (1) a connection pattern 1 with which thevariable current is supplied only to the power-supplying coil 111 byusing only the route A; (2) a connection pattern 2 with which thevariable current is supplied only to the power-supplying coil 112 byusing only the route B; (3) a connection pattern 3 with which thevariable current is supplied only to the power-supplying coil 113 byusing only the route C; (4) a connection pattern 4 with which thevariable current is supplied to the power-supplying coils 111 and 112 byusing the route A and the route B; (5) a connection pattern 5 with whichthe variable current is supplied to the power-supplying coils 112 and113 by using the route B and the route C; and (6) a connection pattern 6with which the variable current is supplied to the power-supplying coils111 and 113 by using the route A and the route C. The switch controlmechanism is able to switch a combination selected from these connectionpatterns 1 to 6 at any timing.

In addition to the above, the switch control mechanism of the currentpath switcher 1311 has a function of executing a stop process of notsupplying the variable current to any of the power-supplying coils 111,112, and 113, with a predetermined combination of a timing and aduration. With this arrangement, the switch control mechanism is able toeasily generate a variable magnetic field with predetermined magneticfield strength in consideration of heat generation and powerconsumption, by adjusting the timing and duration of the stop process.

To be more specific, the switch control mechanism is able to perform apause operation (stop process) of stopping the power supply to all ofthe power-supplying coils 111, 112, and 113 by turning off all switchesof the switch mechanism. In the pause operation, a pause time isselectable from plural pause times (time 1 to time n), and a suitablepause time is selected in consideration of the use and state of themagnetic field formation device 101.

In addition to the above, the switch control mechanism is able todetermine a timing to execute the pause operation based on plural pausepatterns. To be more specific, there are “every 1 pattern” with whichthe pause operation is executed each time one of the connection patterns1 to 6 is completed, “every 2 patterns” with which the pause operationis executed each time two of the connection patterns 1 to 6 arecompleted, and so on. As one of these options is selected, various pauseoperations are executable at a desired timing.

For example, the current path switcher 1311 is able to perform apowering operation in which a route A connection state with theconnection pattern 1, the pause operation, a route B connection statewith the connection pattern 2, the pause operation, a route C connectionstate with the connection pattern 3, and the pause operation arerepeated in order. Furthermore, for example, the current path switcher1311 is able to perform a powering operation in which the route Aconnection state with the connection pattern 1, the route B connectionstate with the connection pattern 2, the route C connection state withthe connection pattern 3, and the pause operation are repeated in order.

The current path switcher 1311 may be constituted by a circuit having aprogrammability such as a microcomputer and an operation of switchingthe variable current may executed by software, or may be constituted bya combination of ICs and the switching operation may be executed byhardware.

(Application Example of Magnetic Field Formation Device)

The following will describe a case where the magnetic field formationdevice 101 structured as above is used in a power-supplying device asshown in FIG. 9. To put it differently, the following will describe acase where the magnetic field formation device 101 is mounted on thecharger 7 as a power-supplying device and electric power is supplied ina wireless manner to the power-receiving module 9 which is apower-receiving device of the driving device 5 mounted in the charger 7.

The charger 7 (power-supplying device) on which the magnetic fieldformation device 101 is mounted and the driving device 5 (secondarybattery 10, power-receiving module 9) constitute a powerreceiving/supplying device 1 or a power receiving/supplying system. Toput it differently, the power receiving/supplying device 1 includes thedriving device 5 including the power-receiving coil mechanism 2receiving power by a magnetic field and the charger 7 supplying power tothe driving device 5 by wireless transmission.

In the power receiving/supplying device 1, the charger 7 and the drivingdevice 5 may be treated in combination. While the description belowdeals with a case where the power-receiving coil mechanism 2 receivespower by magnetic field resonance, the disclosure is not limited to thisarrangement and it may receive power by electromagnetic induction.

(Application Example of Magnetic Field Formation Device: Charger andHousing Cup)

The charger 7 includes the housing cup 6 in which the driving device 5such as a mobile device including a power-receiving device is mountedand the magnetic field formation device 101 which is configured togenerate a variable magnetic field at the housing region B of thehousing cup 6 to allow the power-receiving module 9 to receive powerirrespective of the direction and position of the power-receiving module9. The housing cup 6 may be arranged such that plural driving devices 5are simultaneously placed at the housing region B. To put itdifferently, the housing region B of the housing cup 6 may have acapacity capable of simultaneously storing plural driving devices 5.

The magnetic field formation device 101 is provided in a casing of thecharging case 60 in which the housing cup 6 is provided. When themagnetic field formation device 101 is employed in the charger 7, thepower-supplying coils 111 and 112 function as power feeding coils 31whereas the power supplying resonator 121 functions as a power-supplyingresonator 32. A power-supplying coil mechanism 3 including the powerfeeding coils 31 and the power-supplying resonator 32 is connected to anoscillation control circuit 81 which is an IC chip in which theoscillation controller 131 outputting a variable current is embodied.

The oscillation control circuit 81 and the power-supplying coilmechanism 3 are combined as a power-supplying module 8 in order toimprove the handleability. The oscillation control circuit 81 isconnected to a USB terminal 61. The USB terminal 61 is connectable to anunillustrated USB cable of an external device such as a personalcomputer provided outside the charger 7, so that 5V DC power can besupplied from the external device to the oscillation control circuit 81.Instead of the USB terminal 61, the charger 7 may be connected to a homeAC power cord, and DC power converted from AC power by a rectifyingcircuit and a converter may be suppliable to the oscillation controlcircuit 81.

(Application Example of Magnetic Field Formation Device: Driving Device)

An example of the driving device 5 charged and driven by theabove-described charger 7 is a mobile device. The mobile deviceencompasses a handheld device which can be carried on a hand and ahuman-wearable device which can be worn a human body. Specific examplesof the mobile device include a portable computer (a laptop PC, a notePC, a tablet PC, or the like), a headset, a camera, an audio visualdevice (a portable music player, an IC recorder, a portable DVD player,or the like), a calculator (such as a pocket computer and an electroniccalculator), a game console, a computer peripheral (a portable printer,a portable scanner, a portable modem, or the like), a dedicatedinformation device (an electronic dictionary, an electronic notebook, anelectronic book, a portable data terminal, or the like), a portablecommunication terminal, a voice communication terminal (a portablephone, a PHS, a satellite phone, a third party radio system, an amateurradio, a specified low power radio, a personal radio, a citizen radio,or the like), a data communication terminal (a portable phone, a PHS (afeature phone and a smart phone), a pager, or the like), a broadcastingreceiver (a television receiver and a radio), a portable radio, aportable television receiver, a one-seg receiver, another type of device(a wristwatch and a pocket watch), a hearing aid, a handheld GPS, asecurity buzzer, a flashlight/pen light, a battery pack, and the like.Examples of the above hearing aid include an ear-hook hearing aid, anear hole fitting hearing aid, and a glasses-type hearing aid. Thedriving device 5 may be a desktop device such as a personal computer.

(Application Example of Magnetic Field Formation Device: Driving Device:Power-Receiving Coil Mechanism)

The driving device 5 includes the power-receiving coil mechanism 2 whichis configured to receive power by a magnetic field. In addition to thepower-receiving coil mechanism 2, the driving device 5 includes: a powercontrol circuit 91 to which power is supplied from the power-receivingcoil mechanism 2; and a magnetic member 4. The power-receiving coilmechanism 2, the power control circuit 91, and the magnetic member 4 areintegrated as a power-receiving module 9. The power-receiving module 9is connected to a secondary battery 10.

The power-receiving coil mechanism 2 is configured to receive power insuch a way that magnetic field resonance is caused by a variablemagnetic field in the housing region B (predetermined region A). To bemore specific, the power-receiving coil mechanism 2 includes apower-receiving coil 21 and a power-receiving resonator 22 provided onthe inner circumferential side of the power-receiving coil 21. The“magnetic field resonance” indicates a resonance phenomenon ofsynchronization at a resonance frequency of a variable magnetic field.Examples of the types of coils used in the power-receiving coil 21 andthe power-receiving resonator 22 include: a spiral type, a solenoidtype, and a loop type. In regard to the positional relation between thepower-receiving coil 21 and the power-receiving resonator 22, thepower-receiving coil 21 may be provided on the inner circumferentialside or the outer circumference side of the power-receiving resonator22, or the power-receiving coil 21 and the power-receiving resonator 22may be provided not to overlap each other in the radial direction.

The driving device 5 includes the magnetic member 4 provided at thepower-receiving coil mechanism 2. The magnetic member 4 increases themagnetic field strength by increasing the mutual inductance of thepower-receiving coil mechanism 2 and increasing the magnetic fluxdensity. As the magnetic field strength of the power-receiving coilmechanism 2 is increased by the magnetic member 4, the chargingcharacteristic is maintained to be high in the power-receiving coilmechanism 2, and power at least at a desired level is receivable with animproved degree of freedom in the layout of the power-receiving coilmechanism 2. The power-receiving coil mechanism 2 preferably includesthe magnetic member 4 but may not include the magnetic member 4.

The magnetic member 4 is provided on the inner circumferential side ofthe power-receiving coil mechanism 2. While the positional relationbetween the power-receiving coil mechanism 2 and the magnetic member 4in the axial direction, i.e., the positional relation when viewed in thedirection orthogonal to the axial direction is not particularly limited,these members are preferably provided so that the power-receiving coilmechanism 2 is provided at an intermediate portion between one end sideand the other end side of the magnetic member 4. This “intermediateportion” between one end side and the other end side of the magneticmember 4 indicates a part of a region sandwiched between the one end andthe other end, excluding the one end and the other end.

The positional relation between the power-receiving coil mechanism 2 andthe magnetic member 4 in the axial direction is further preferablyarranged so that the power-receiving coil mechanism 2 is provided at acentral portion between one end side and the other end side of themagnetic member 4. The positional relation between the power-receivingcoil mechanism 2 and the magnetic member 4 in the axial direction ispreferably arranged such that the charging characteristic of themagnetic member 4 is not significantly different between a case wherethe coil surface 2 a of the power-receiving coil mechanism 2 on one sidefaces a magnetic field generating surface 3 a of the power-supplyingcoil mechanism 3 and a case where the coil surface 2 b of thepower-receiving coil mechanism 2 on the other side faces the magneticfield generating surface 3 a.

The power-receiving resonator 22 of the power-receiving coil mechanism 2is provided so that the power-receiving coil 21 is disposed on the outercircumference side. To be more specific, the power-receiving coilmechanism 2 is arranged such that the power-receiving resonator 22 isprovided between the power-receiving coil 21 on the outermostcircumferential side and the magnetic member 4 on the innermostcircumferential side. While the positional relation between thepower-receiving resonator 22 and the power-receiving coil 21 in theaxial direction is not particularly limited, these members arepreferably provided so that the power-receiving coil 21 is provided atan intermediate portion between one end side and the other end side ofthe power-receiving resonator 22. The positional relation between thepower-receiving resonator 22 and the power-receiving coil 21 in theaxial direction is further preferably arranged so that thepower-receiving coil 21 is provided at a central portion between one endside and the other end side of the power-receiving resonator 22.

The magnetic member 4 is made of resin in which magnetic powder isdispersed. The resin used for the magnetic member 4 may be thermosettingresin or thermoplastic resin, and is not particularly limited. Examplesof the thermosetting resin include epoxy resin, phenol resin, melamineresin, vinyl ester resin, cyano ester resin, maleimide resin, andsilicon resin. Examples of the thermoplastic resin include acrylicresin, vinyl acetate based resin, and poly vinyl alcohol based resin.The present example adopts a resin whose main component is epoxy resin.

Further, soft magnetic powder is used as the magnetic powder dispersedin the resin. Examples of the soft magnetic powder include pure Fe,Fe—Si, Fe—Al—Si (sendust), Fe—Ni (permalloy), soft ferrites, Fe-baseamorphous, Co-base amorphous, and Fe—Co (permendur); however, is notparticularly limited. The shape of the magnetic member 4 is suitablydetermined, too.

(Application Example of Power Receiving/Supplying Device 1: DrivingDevice: Power Control Circuit)

The power control circuit 91 is mounted on a circuit substrate.

As shown in FIG. 10, the power control circuit 91 has a function ofcontrolling the charging of the secondary battery 10. The power controlcircuit 91 may be a circuit further having a function of controlling thedischarging.

To be more specific, the power control circuit 91 includes arectification stabilization unit 911 which is configured to output DCpower by rectifying AC power supplied from the outside via thepower-receiving coil mechanism 2 outputting the DC power, a chargingunit 912 configured to supply the DC power outputted from therectification stabilization unit 911 to the secondary battery 10 at acharging voltage, and a transformation unit 913 configured to execute asignal process. The transformation unit 913 is connected to a drivingmechanism 11 which is driven by the charged power of the secondarybattery 10.

The rectification stabilization unit 911 is arectification-stabilization IC, for example. Therectification-stabilization IC is an IC in which functions such as fullbridge synchronous rectification, voltage conditioning and wirelesspower control, and protection from a voltage, current, or temperatureanomaly are integrated into one chip. The rectification stabilizationunit 911 may not be provided when the power outputted from thepower-receiving coil mechanism 2 is DC power.

The charging unit 912 is an IC (charging circuit) for a constantcurrent/constant voltage linear charger, and has functions such as afunction of notifying that the charging current has been reduced to apredetermined setting value, a function of ending the charging using atimer, a function of stabilizing the charging current by means ofthermal feedback, and a function of limiting the chip temperature in ahigh-power mode or in high ambient temperatures.

The transformation unit 913 is a transformer circuit which functions asa transformation unit performing signal processing of converting thecharged power of the secondary battery 10 to the driving power for thedriving mechanism 11 and outputting the converted power. As thetransformation unit 913, a linear regulator may be employed for voltagedropping, or a switching regulator or a charge pump may be employed forvoltage boosting and voltage dropping. An example of each regulator isone adopting a semiconductor elements so the current is switched on andoff at a high speed.

(Application Example of Power Receiving/Supplying Device 1: DrivingDevice: Power Control Circuit with High-Capacitance Capacitor)

As shown in FIG. 11 and FIG. 12, the power control circuit 91 mayinclude a high-capacitance capacitor as a first-stage power storage unit920. The first-stage power storage unit 920 has a capacity ofdischarging at a voltage equal to or higher than the minimum operatingvoltage of an electric part on a subsequent stage, and is preferablyprovided in cases where a received voltage varies. The “electric part”encompasses not only a secondary battery and an electronic circuitsubstrate but also all driving devices driven by supplied power. The“minimum operating voltage” indicates the minimum voltage with which anelectric part is properly driven. For example, the minimum operatingvoltage of a secondary battery is the minimum voltage with which acharging IC of the secondary battery is properly driven.

The first-stage power storage unit 920 is particularly preferable whenswitching of conduction to the power feeding coil 31 is performed by thecurrent path switcher 1311 shown in FIG. 7. To be more specific, thedriving device 5 (power-receiving device) including the power controlcircuit 91 may be configured to receive power by a variable magneticfield generated at the predetermined region A by the magnetic fieldformation device 101, and may include: the power-receiving coilmechanism 2 (power-receiving mechanism) configured to receive power bythe variable magnetic field; and the first-stage power storage unit 920(high-capacitance capacitor) having a capacity of being charged by acurrent received by the power-receiving coil mechanism 2 and dischargingat least at the minimum operating voltage of the secondary battery 10,etc. (electric part) on a subsequent stage while the current pathswitcher 1311 is performing the switching of the output target.

The driving device 5 may include: the power-receiving coil mechanism 2(power-receiving device) configured to receive power by a variablemagnetic field; and a high-capacitance capacitor having a capacity ofbeing charged by a current received by the power-receiving coilmechanism 2 and discharging at least at the minimum operating voltage ofthe secondary battery 10, etc. (electric part) on a subsequent stagewhile the current path switcher 1311 is performing the stop process.

According to the arrangement above, even when an induced current cannotbe obtained from the power-receiving coil mechanism 2 on account of theswitching process or the stop process performed for the power feedingcoil 31, the charging unit 912 or the like is stably driven because thefirst-stage power storage unit 920 performs the discharge at least atthe minimum operating voltage of the charging unit 912 or the like.

The first-stage power storage unit 920 (high-capacitance capacitor) mayhave a capacity of discharging at least at the minimum operating voltageof an electric part on a subsequent stage during the stop process inwhich the current path switcher 1311 does not supply a variable currentto the power feeding coil 31 (power-supplying coil), in addition to theperiod during which the switching of the output target is beingperformed by the current path switcher 1311. According to thisarrangement, in addition to the period during which the switching of theoutput target is being performed by the current path switcher 1311, evenwhen an induced current cannot be obtained from a power-receiving coildue to the stop process for the power-supplying coil and the powersupplying resonator, the electric part is stably driven as thefirst-stage power storage unit 920 performs the discharge at least atthe minimum operating voltage of the electric part.

(Application Example of Power Receiving/Supplying Device: DrivingMechanism: Driving Device)

Examples of the driving mechanism 11 include a mechanism in which acomponent converting electric power to kinetic energy such as a speakerand a motor is incorporated, a light emitting mechanism or anillumination mechanism in which a component converting electric power tooptical energy such as an LED light source and a laser light source isincorporated, and a microcomputer. Apart from these mechanisms, anytypes of mechanism driven by electric power may be used as the drivingmechanism 11. The power-receiving coil mechanism 2 is configured tocorrespond to wireless power supply with which power supply is carriedout in a mechanically contactless state. Examples of the wireless powersupply include electromagnetic induction and magnetic field resonance(magnetic resonance).

(Application Example of Power Receiving/Supplying Device: DrivingDevice: Secondary Battery)

As the secondary battery 10, any type of batteries which are chargeableand rechargeable can be used. Examples of the secondary battery 10include a lead storage battery, a valve-regulated lead storage battery,a lithium ion battery, a lithium ion polymer battery, a lithium ironphosphate ion battery, a lithium-sulfur battery, a lithium titanatebattery, a nickel-cadmium storage battery, a nickel-hydrogenrechargeable battery, a nickel-iron battery, a nickel-lithium battery, anickel-zinc battery, a rechargeable alkali battery, a sodium-sulfurbattery, a redox flow battery, a zinc-bromine flow battery, a siliconbattery, and a Silver-Zinc battery.

Although the above descriptions have been provided with regard to thecharacteristic parts so as to understand the invention more easily, theinvention is not limited to the embodiment as described above and can beapplied to the other embodiments and the applicable scope should beconstrued as broadly as possible. Furthermore, the terms and phraseologyused in the specification have been used to correctly illustrate thepresent invention, not to limit it. In addition, it will be understoodby those skilled in the art that the other structures, systems, methodsand the like included in the spirit of the present invention can beeasily derived from the spirit of the invention described in thespecification. Accordingly, it should be considered that the presentinvention covers equivalent structures thereof without departing fromthe spirit and scope of the invention as defined in the followingclaims. In addition, it is required to sufficiently refer to thedocuments that have been already disclosed, so as to fully understandthe objects and effects of the present invention.

REFERENCE SIGNS LIST

-   1 power receiving/supplying device-   2 power-receiving coil mechanism-   3 power-supplying coil mechanism-   4 magnetic member-   5 driving device-   6 housing cup-   7 charger-   8 power-supplying module-   9 power-receiving module-   10 secondary battery-   21 power-receiving coil-   22 power-receiving resonator-   31 power feeding coil-   32 power-supplying resonator-   51 housing-   111 power-supplying coil-   112 power-supplying coil-   131 oscillation controller-   1111 power supplying sub coil-   1112 power supplying sub coil-   1311 current path switcher-   1312 oscillator-   A predetermined region-   B housing region

The invention claimed is:
 1. A magnetic field formation deviceconfigured to generate a variable magnetic field at a predeterminedregion, the magnetic field formation device comprising: at least onepower supplying resonator configured to generate the variable magneticfield, the at least one power supplying resonator including a coilsurface; a plurality of power-supplying coils configured to generate aninduced current in the at least one power supplying resonator, each ofthe plurality of power-supplying coils having a coil surface, all of theplurality of power-supplying coils and the at least one power supplyingresonator being disposed so that the respective coil surfaces oppose thepredetermined region, and at least one of the plurality ofpower-supplying coils is disposed so that a coil surface directionintersects with a coil surface direction of at least one of anotherpower-supplying coil of the plurality of power-supplying coils; and acurrent output controller configured to (i) output a variable current toone output target of a plurality of output targets, which are at leastone of and not all of the plurality of power-supplying coils, and (ii)repeatedly switch the one output target to which the variable current isoutput to another output target of the plurality of output targets. 2.The magnetic field formation device according to claim 1, wherein: allof the power-supplying coils are disposed so that the respective coilsurfaces oppose the predetermined region, and the coil surface directionof at least one of the power-supplying coils is disposed to be parallelto the coil surface direction of at least one of another power-supplyingcoil of the plurality of power-supplying coils.
 3. The magnetic fieldformation device according to claim 1, wherein the current outputcontroller executes a stop process of not outputting the variablecurrent to any of the plurality of power-supplying coils with apredetermined condition of a timing and a duration.
 4. The magneticfield formation device according to claim 1, wherein the plurality ofpower-supplying coils are disposed so that respective outer peripheriesof the plurality of power-supplying coils at least partially overlap oneanother.
 5. A power-supplying device comprising the magnetic fieldformation device according to claim
 1. 6. A power-receiving devicecomprising a power-receiving mechanism configured to receive power bythe variable magnetic field generated at the predetermined region by themagnetic field formation device of claim
 1. 7. A power-receiving deviceconfigured to receive power by the variable magnetic field generated atthe predetermined region by the magnetic field formation device of claim1, the power-receiving device comprising: a power-receiving mechanismconfigured to receive power by the variable magnetic field; and ahigh-capacitance capacitor having a capacity charged by a currentreceived by the power-receiving mechanism and discharging at least aminimum operating voltage of an electric part on a subsequent stagewhile an output target of the variable current is switched by a currentpath switcher.
 8. A power-receiving device configured to generate avariable magnetic field at a predetermined region by a magnetic fieldformation device, the magnetic field formation device including (i) atleast one power supplying resonator configured to generate the variablemagnetic field, the at least one power supplying resonator including acoil surface, (ii) a plurality of power-supplying coils configured togenerate an induced current in the at least one power supplyingresonator, each of the plurality of power-supplying coils having a coilsurface, all of the plurality of power-supplying coils and the at leastone power supplying resonator being disposed so that the respective coilsurfaces oppose the predetermined region, and (iii) a current outputcontroller configured to output a variable current to one output targetof a plurality of output targets, which are at least one of and not allof the plurality of power-supplying coils, and repeatedly switch the oneoutput target to which the variable current is output to another outputtarget of the plurality of output targets, the power-receiving devicecomprising: a power-receiving mechanism configured to receive power bythe variable magnetic field; and a high-capacitance capacitor having acapacity charged by a current received by the power-receiving mechanismand discharging at least a minimum operating voltage of an electric parton a subsequent stage while an output target of the variable current isswitched by a current path switcher, wherein: the high-capacitancecapacitor discharges at least the minimum operating voltage of theelectric part on the subsequent stage during a stop process in which thecurrent path switcher does not supply the variable current to any of theplurality of power-supplying coils.
 9. A power receiving/supplyingdevice comprising: a power-supplying device including the magnetic fieldformation device according to claim 1; and a power-receiving deviceincluding a power-receiving mechanism configured to receive power by thevariable magnetic field generated by the power-supplying device.
 10. Amobile device comprising a power-receiving mechanism configured toreceive power by the variable magnetic field generated at thepredetermined region by the magnetic field formation device of claim 1.11. The power-receiving device according to claim 8, wherein at leastone of the plurality of power-supplying coils is disposed so that a coilsurface direction intersects with a coil surface direction of at leastone of another power-supplying coil of the plurality of power-supplyingcoils.